AVO reported that an energetic earthquake swarm on Tanaga Island began on 23 January, with earthquakes located 6-7 km ESE of Takawangha volcano, and was possibly due to brittle failure in the surrounding rock caused by magma movement. AVO raised the Aviation Color Code to Yellow and Alert Level to Advisory.

Geological Summary. Takawangha is a youthful volcano with an ice-filled caldera on northern Tanaga Island, near the western end of the Andreanof Islands. It lies across a saddle from historically active Tanaga volcano to the west; older, deeply eroded volcanoes lie adjacent to the east. The summit of the dominantly basaltic to basaltic-andesite volcano is largely ice covered, with the exception of five Holocene craters that during the last few thousand years produced explosive eruptions and lava flows that reached the lower flanks. No historical eruptions are known, although radiocarbon dating indicates explosive eruptions have occurred within the past several hundred years.

Source: US Geological Survey Alaska Volcano Observatory (AVO)